Decoding The Markings of a UN Packaging

If a shipper understands the code used on UN certified drums, then the symbol and letters placed on the outside of a drum can give all the necessary information to determine what type of contents can be safely stored inside. If a shipper does not understand the code and is shipping a hazardous material, this can lead to a non-compliant and potentially dangerous situation. Below is an example of UN markings one might see on a drum.

The first character used determines the type of container. Here, the number "1" is used because that is the UN code for drums. The letter "A" denotes the container is made of steel and the number "2" indicates it is an open head style. In the next section, the first character is the class rating for UN classifications. An "X" means the drum’s contents belong to the highest hazardous class (X, Y, Z with X being the highest risk and Z being the lowest). The next set of numbers is the tested weight in kilograms, so in our example the drum can hold 430 KG. The "S" indicates that the drum has been approved for holding solids, and the "13" denotes what year the drum was manufactured. Next is the country of origin followed by the unique manufacturer’s code which for Skolnik is “SDCC.”

Although there is no required placement for the marking, they must be placed somewhere easy to see, usually the top of the head or the side of the drum. Every drum that is larger than 100 liters (26.4 gallons) is required to have the markings in a second place, the bottom of the drum. Whereas the first marking can be added to the drum with paint or a label, this second must be permanent on the drum. This second marking can be embossed or etched into the steel as long as it is not removable. This second marking does not require the manufacturer’s code.

There is a minimum size requirement for the size of the letters, but there is not a specified color or font to use. Characters must be at least 12.0mm (0.47") high, and a color that stands out from the metal or paint on the outside of the drum.
It is important to use the drum as it was tested and to follow all Closure Instructions provided by the manufacturer. The number one concern in packaging is to prevent the escape of any contents, and only a drum manufactured and used properly can accomplish this goal.